Polymer fibers are useful in a variety of products including medical and hygiene products, carpets and floor coverings, apparel and household textiles, filtering media, agro- and geotextiles, automotive interior, filler for sleeping bags, comforters, pillows, and cushions, cleaning wipes, abrasive articles, and numerous others.
A polypropylene fiber including a beta-nucleating agent having a porous structure for use in filters is disclosed in DE 102007050047, published Apr. 23, 2009.
Various multi-component fibers are known. Examples include fibers that have a low temperature melting or softening sheath covering a higher melting core. Multi-component structures may be useful, for example, for fiber bonding, wherein the sheath, for example, when melted or softened serves as a bonding agent to bond individual fibers together.
In other technologies, a variety of different personal hygiene articles (e.g., absorbent articles such as diapers, adult incontinence products, and sanitary napkins) that include different printed and/or colored regions are available in the market. Printing or coloring on such articles can be attractive to the consumer and help the consumer differentiate between different brands. Some manufacturers of absorbent articles print with multi-colored graphics that are a signature of their brand. Others may use monochromatic printing on the articles. Printing approaches to providing a differentiated product generally use ink, colored adhesives, or heat- or pressure-activated chemical colorants, each of which adds cost to the product that is passed on to consumers. Some recent examples of absorbent articles with patterns or colors include those described in U.S. Pat. No. 8,324,444 (Hansson et al.) and U.S. Pat. Appl. Pub. Nos. 2011/0264064 (Arora et al.) and 2012/0242009 (Mullane et al.).